When Knox is tripped it sets off the root check. Your banks misleading statement is due to their own confusion. Knox is no longer active so it can’t guarantee there is no root access. The OS basically says it’s untrusted/insecure due to lack of Knox and always says it’s rooted regardless of that actually being true. You can hide root for all apps that check. Do note that while you can return the functionality of third party apps, Samsung baked in apps can be hit or miss. It’s a game of cat and mouse. I speak from experience.
Additionally here are some other conversations about it: